Master Coding Skills &
System Design.

Master Python OOP — class inheritance, super(), method overriding, polymorphism, and dunder methods for operator overloading and protocol support.

Understand database sharding — vertical vs horizontal partitioning, shard key selection, consistent hashing, hot shards, and resharding.

Learn PHP 8 match expression — strict comparison without break, returning values, multiple arms, and when to use match vs switch.

Compare RabbitMQ and Kafka — push vs pull delivery, message replay, throughput, and code examples in Python for both producers and consumers.

Understand JavaScript memory — stack vs heap, mark-and-sweep GC, common memory leaks (event listeners, intervals, closures) and how to fix them.

Build Segment Tree and Fenwick Tree from scratch — range sum queries, point updates, and when to use each for competitive programming.

10 SQL optimization techniques with before/after examples — indexes, covering indexes, NOT EXISTS vs NOT IN, LIMIT pushdown, and partition pruning.

Master PHPUnit — test classes, assertions, setUp/tearDown, mocking dependencies, data providers, and test coverage reporting.

Understand microservices vs monolith trade-offs, when to extract a service, the modular monolith middle ground, and migration strategy.